Virus
by anonymousheart
Summary: SHIELD is on high alert after some seemingly harmless office buildings became the victims of a band of terrorists. They've sent in a small team to comb through the ruins in search of survivors, in the hope that someone will know why. But when Agent Barton meets a mysterious girl- the only survivor- what he discovers could change the world. Rated T because I'm paranoid.
1. Chapter 1

**This is my first fanfic, so please, review! I'd like some constructive criticism to make my story better :). Enjoy!**

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**Chapter One: The Girl in the Rubble**

Most of the buildings had been reduced to no more than the smoldering shells of their former selves. The air was tainted with the acrid smell of smoke from the still burning dry wall, and it stung the girl's lungs even though she was now in an area of the compound that hadn't been so badly damaged.

But still, she sat there silently, not daring to move from the shadowy crevice of the large, ruined room. She had seen what those people had done, and she wasn't sure they'd given up yet. Their days of terrorism weren't over, and if they found her… The girl refused to consider the outcome.

Isamu had told her that there would be people who would come looking for her. He had said that she would be found eventually, and that that was putting it lightly. But it all depended on how quiet she was. It had always been about quiet with him. _Do not speak, child. You mustn't let them hear. If they can hear you, they can find you. You cannot let yourself be found, not yet. It must be by right person._

She was still, her breathing, although quick and shallow, was still silent as she'd been taught. Isamu had been her only family, for eleven whole years, preparing her to take upon his burden. The secret. _The secret that could change the fate of the world_. She'd received Isamu's spiel so many times she'd lost count. But she never forgot how important it was that she tread lightly and keep her mouth shut.

_If the wrong people catch you, they will imprison you. It does not matter to them whether you be young or old, male or female. These people will stop at nothing to get the information out of you. And that means they will torture you to no end to get it, if they see it necessary. But you must never — never give in, no matter how great the pain. It is too great a burden to set upon such innocence, I know. But there are few who will understand among adults. You must be bred and raised to meet the challenge, and if that is what we must to save ourselves, than that is that_, he would say.

And she never disobeyed. Not once.

She had been taken as a child and raised to stay silent, oh so silent. When Isamu had chosen her, she had accepted her fate. He had deemed her the only one of the group able to keep her composure and stay silent for long periods of time. And from that day forth, he had had her memorize the secret. Their secret. Because the rule was that only two people could know at one time, two people of six billion. That was, until their knowledge was needed. Then, and only then, could anyone else know.

For eleven years, they were left in peace. Eleven years, they had spent together, him teaching her everything she needed to know, from science to history. She could speak almost ten languages, she could recite almost any famous speech, and she could explain almost any scientific theory in a way that even a three year old could understand.

But she didn't. She couldn't. Especially not then, on that fateful day when, much to her and Isamu's dismay, they were found. Found by the wrong people. And as Isamu lay there on the cold tile floor, a growing puddle of his own blood pooling around them from the bullet wounds in his torso, he had gazed solemnly into her scared green eyes with his own, dark brown ones, the ones she'd always looked to for guidance or protection, and whispered, "They are here, child. There is nothing you can do for me. There will be another group of people who come to find survivors. They call themselves SHIELD. From what I understand, they are not bad like my killers. I do not know for certain, but you will have to decide whether you can trust them or not. I cannot assure you that you are safe from harm in their custody. Now run. Hide. And be silent as butterflies' wings. The burden of the secret is now for you and you alone. "

So she ran. Right into the building she was in a few days later, waiting in a scared silence as the sirens drew nearer and nearer. She had been terrified, and altogether she wasn't paying enough attention. Before she knew what was happening, she'd tripped down a flight of stairs, landing almost every single time as she fell on her left leg, and ended up lying helplessly on the ground, unable to stand as pain ripped through her entire body and left her struggling not to scream. She'd limited herself to merely sobbing. The men could find her if she got any louder.

But they never did.

She had pulled together enough to drag herself into the nearest room, an office, and pull herself underneath a desk in one of the cubicles. With her good leg folded underneath her, the shattered one straight out in front of her and her back flush to the metal and cloth wall of the cubicle, she rested her head against the other wall and forced herself to sleep. The loss of Isamu, the closest person she'd ever had to a father, would plague her less as she dreamt.

Now, almost two days later, people had returned to the rubble to find survivors. Already, someone had walked through the room, a man wearing a red, white and blue uniform, and carrying a matching shield. From what she could gather from his communicator, they were finding no one. Not that they would. This certain group of terrorists were known to be thorough.

Another was making their way slowly through the office, now. Another man dressed in all black, armed with a bow and quiver. The girl swallowed quietly, closely observing the way he moved through the room, thoroughly searching in every hiding place. He was getting closer and closer, and she was starting to notice more about him. The expert way he placed his feet when moving through the wreckage, careful not to trip over the overturned desk chairs and file cabinets, but at the same time remaining silent as he did so. _You must be found by the right people, child,_ Isamu had said. You will have to decide whether you can trust them or not.

The girl took in a deep breath and released it slowly. On the other end of the man's communicator, a deep voice was ordering the final sweep of searchers to start heading back. They weren't finding anything, and they probably wouldn't be able to.

He turned to leave, and the girl made her decision. She wouldn't get anywhere with her mangled leg, and she couldn't bear the freezing winter temperatures any longer, or the combined pain of her dry throat, empty stomach, awful headache and injured leg. So she ignored her instinctual impulse to remain silent. She went against what Isamu had told her.

As her last hope started to walk away, the girl made a small noise in the back of her throat, quieter than she'd have liked, but loud enough. The man turned, bow raised, and his eyes scanned the room again. She gave another whimper, a bit louder, and he made his way, quick and quiet, towards the source of the noise. With her third and final attempt, he found her. His unnatural electric blue bored into her emerald green as their eyes met. With a wince she pulled her left leg towards her uncertainly, still unsure whether to trust him or not. His gaze lowered, and a crease of worry formed between his eyebrows when he saw her leg. "That's not good," he muttered.

The man shoved the desk chair out of the way forcefully and reached under the desk to pull her out, but the girl flinched away, fear back in her eyes. He stopped and studied her again. "How long have you been here?" he asked finally, sitting down.

"Two days," she replied, her voice hoarse and rusty, evidence of the fact she'd been almost completely silent for the past few weeks as she and Isamu fled from his home in Japan to Canada, and then to her original home in the United States.

The man grunted and gestured to her leg. "You can't put any weight on that, can you? Is that why you didn't leave?"

She shook her head. "Too dangerous."

He nodded thoughtfully. "Have you been under this desk for that entire time?" She nodded. He sighed. "I hope there's something we can do to fix it up for you. You have family?" She hesitated before shaking her head.

"He's dead. Downstairs."

"I'm sorry about that." The man sighed. "So, you haven't had anything to eat or drink for two whole days, huh?" She shook her head. "You must be a mess, then. Most people can only survive without water for three to four days. Let's get you out of here, okay?" She hesitated again. He groaned. "I'm not leaving you, kid. We think the terrorists could still come back. I'm not gonna leave you to die. But you have to trust me. Look, I've seen a lot of things you wouldn't believe. I've fought wars against entire armies with only a team of five on my side. I've been all over the world. I'm a master assassin, an agent of SHIELD, and an Avenger on the side. I help defend the world from the unknown. It's not a cakewalk, either."

She felt her distrust ebb away as the man, Clint, told her about himself, just talking. How he'd become an assassin. How he'd been assigned to kill his partner, Natasha, when she had been an assassin for a rival organization in a different country, and how he'd made another call. How he and Natasha had handled the Hulk and managed to convince him join the Avengers. How he'd fought to defend Manhattan from the Chitauri invasion with only five other people by his side, and how they'd won.

For almost an hour, maybe even two, he told her everything. And when he'd finished, he said, "The most recent mission we were assigned took Tasha and me to this desert in California. I honestly can't tell you whether it's the Mohave or the Sonoran, and I couldn't care less. All I can really tell you is that we'd come to this little place in the middle of the desert that had been attacked by some of the most thorough terrorists I've ever seen. We all split up to look for survivors, checking out these eight building, but no one found anything. Director Fury had just called for us to start heading back, so I did, but then I heard this noise. I turned around, but I couldn't see anything. I thought I was going crazy, but then I heard it again. When I finally found the source, it was a girl. Let me tell you, she was a mess. Her face and her arms were all cut up, her leg was really badly broken, and it was just — _awful_. She was starving and thirsty and in really bad shape. And she was the only one left in the entire place who was still alive."

Clint gave her a deep look. "You want to tell me how it ends?" The girl hesitated and took a deep breath. Then she slowly started to unfold herself from the corner. Clint smiled. "There we go," he said, reaching out to help her out from under the desk. When they'd finally managed to get her out of the corner and semi-standing next to him, her leg was still dangling limply at her side, hanging at an odd angle. "Can you put any weight on it?" he asked.

She tried. Her efforts, although brave, only ended with her nearly falling back to the floor. Clint supported her. "Okay, I guess that's a no," he muttered, slinging his bow over his shoulder. "I'll have to carry you. Just give me a minute." He pulled his communicator from his belt. "Fury, I've got one here," he said. They waited for a moment, but there was no reply. Frowning, Clint tried again, but they got the same result. "What the – Oh, damn it!" he growled, shaking the device. "The battery's dead. I should've known something was off. Fury would've called for me to come back before now. They're probably looking for me," he muttered, jamming it back into place on his belt. "We've gotta go."

He picked her up lightly with one arm around her shoulders and the other one supporting her legs. "Good Lord, you're skinny!" he exclaimed, shifting her in his arms a bit. She looked at the ground, embarrassed, and wrapped her arms around his neck for stability. "Well, we'll see what we can do about that when we get there. Hold on tight, kid. I'm gonna run us down there."

Clint wasn't kidding when he said she'd have to hold on. The SHIELD agent was running at top speed, easily hurdling furniture and piles of debris from the ruined building. Whatever the punishment was for lateness or disobeying orders, Clint apparently didn't want to make it worse for himself. Twice, he almost knocked her leg into something, but they were lucky. Clint managed to stay on his feet, and the girl managed to hold on to him.

As they reached the second floor, another man came running to meet them, and Clint skidded to a stop. "Barton!" the man exclaimed. "Where were you? Fury must've called your communicator twenty times, and you didn't answer!"

"Well, sorry about that, Phil," Clint grunted. "My communicator died on me and I didn't notice. Anyway, Coulson, look at what I found." Agent Barton shrugged his shoulders, raising the girl a bit. "Seventh floor, curled up under a desk."

Agent Coulson seemed to realize for the first time that Clint was carrying her. "Oh! Was she stuck or something?"

"Nah, she just didn't trust me. That's what took me so long. Anyway, I forgot to ask, what's your name, kid?" Clint and Coulson looked at the girl expectantly.

She swallowed. "Don't have a name."

There was a moment of silence. Then Agent Coulson said, "What? You don't have a name?"

"Well no. Isamu thought I didn't need one, so he never gave me one."

"Who's Isamu?" Clint asked.

"He was my guardian. He's dead, now. He was shot when the terrorists came."

"Ah, I see now. No parents?"

The girl gave a weak smile. "I have parents. I just don't know who they are. I was taken from them at birth," she said.

"Why?" Phil asked.

"Because that's how they do it. They gather up a group of children, raise them to age four, and the one who knows the secret chooses an heir. The other children are adopted out to new families. That's how it's been for three generations."

"That sounds like a cult," Agent Barton said, frowning.

"In a way, it is." The girl paused. "The others will come for me, soon, to take me back to Japan. That's where it started."

"Where what—" Phil started, but he was cut off by his communicator.

"Has anyone found anything? Any sign of Barton?" came a man's deep voice.

"Nope," came a woman's voice. "Nothing over here."

"Alright, Hill, head on back. Romanoff?"

Another woman's voice answered. "No," she replied. The girl could hear a faint hint of desperation in her voice. "I haven't."

"Come back, then. Maybe Coulson has something."

"I'm not coming back until we've found him," the woman snapped back immediately. "He's my partner, if he's in trouble, then I need to know."

"He's fine, Natasha," Coulson said into the communicator. "I found him."

"Tell him he'd better have a pretty damn good excuse for me when he gets back, Coulson," the man's deep voice replied.

"His comms died, Director Fury," Coulson said, "so he didn't receive any alert to head back."

"Then tell him he's in trouble with me for almost giving us a heart attack," Agent Romanoff answered.

"It wasn't his fault, Romanoff, now get back to the checkpoint," Director Fury snapped. "Coulson, let me talk to Barton."

"Uh, his hands are kind of full at the moment, sir—"

"What do you mean?" Director Fury asked, a new interest in his voice.

"He found a survivor, sir. A very _interesting_ survivor. We're bringing her down as we speak." Coulson nodded to Clint and started to lead the way downstairs at a much slower pace than Clint had been going only minutes earlier.

"Who is she?" Fury asked.

"Well, we don't know. She doesn't know, for a matter of fact. Says she doesn't have a name."

There was a pause. "No name?"

"No sir. All we have to identify her is that she was taken from her family as an infant and raised in Japan by some sort of cult. Says she has a secret."

When Fury answered this time, there was no hesitation in his voice. "Bring her in."


	2. Chapter 2

**Please, feel free to review. I'd like some constructive criticism to make the story better.  
****Enjoy!**

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**Chapter Two: Revealing a Secret**

Natasha was struggling to decide whether she was angry, relieved, or if she wanted to pretend that Clint's disappearing stunt had never happened. She stood, pacing, next to SHIELD's checkpoint, in the middle of all eight buildings. Well, what had been buildings. They didn't look like much anymore.

It had been five minutes since she'd arrived, and Fury had told her to wait. No one was authorized to enter the building now. It was clear that there was only one survivor from the attack, and there was no point rushing to the aid of two perfectly capable agents, especially since they had each other. Natasha didn't like being held up at the checkpoint while everyone regrouped and waited restlessly for Clint and Phil's return with the survivor.

Agent Hill was one of several agents who'd volunteered to question this mysterious figure as soon as she was fixed up, but the Director had turned them down. "We'll see what Coulson and Barton have gotten out of her already before jumping to conclusions. Yes, she does seem very interesting. Almost any sentence can be made interesting by throwing in the word 'cult,' however, and we have no idea what we could be dealing with. She may not even be telling us the truth."

Natasha grit her teeth and flexed her fingers in agitation. She had never been good at waiting for things to happen. Patience, for her, came at a price. As long as she was doing something, something that had the potential to give her results, she was okay. When she was interrogating someone, for instance, she was fine. Patience came naturally then. It was like a game. If you ask them the right questions, you'll get your reward in their answers. If she was tied up with professionally done knots, she would be patient while undoing her bonds. The reward for that patience: freedom.

But standing around while she could be doing something? That was just torture.

"Speak of the devil, look what the cat dragged in," commented one of the agents, straightening up to get a better look at the doors of the building. Natasha's eyes immediately found the silhouettes in the half melted doorway, Phil's tall, lean figure leading Clint's stockier one. Her gaze settled on the small figure in Clint's arms. She took a sharp breath in. The survivor was only a child.

A round of applause and cheering erupted among the other agents as the small group emerged from the shadow of the ruin and into the fading winter sunlight. Natasha allowed herself a small smile when she saw the almost smug grin on Barton's face, a look that said, See what I found?

Natasha made her way towards her partner, pushing her way through the crowd of thirty or so agents that had all seemed to have had the same idea. "Back off!" Fury called, a note of amusement in his voice at the commotion. Natasha smirked. Sometimes Fury seemed to act like his agents were more like his nieces and nephews rather than his workers.

No one liked his instructions, but everyone cleared off so Clint could get the girl to the medics. As he and Phil walked by, Natasha fell into step with them. "What took you so long?" she growled.

"Hey, Tasha!" Clint said cheerfully, ignoring her question. "Kid, this is my partner, Natasha. Nat, this is – well, for the moment at least, she's still Kid. Say hi."

"Hello," the girl said, turning her politely curious green gaze to Natasha's eyes, also green but a slightly darker shade. Natasha was surprised at the faint Japanese lilt to her voice, barely noticeable, but still there.

"Hey, Kid," Natasha said. She was slightly haunted by the she and girl's striking resemblance, with matching red curls, pale skin, and slender figure. "Good Lord, you're just skin and bones."

The girl nodded and averted her eyes. "I don't eat much," she said shortly in that odd accent of hers.

"Agent Barton," Director Fury said, coming towards them, Agent Hill following eagerly at his heels. "What do we have here?"

"Director Fury, Kid. Kid, Director Fury. He's the – well, the equivalent to the king of SHIELD," Clint said, shifting her in his arms.

"So, no name. How did _that_ happen?" Director Fury asked.

The girl said nothing. She blinked, shooting Clint a quick glance, as if asking permission. "Well? Tell him, Kid," Clint said.

"I was taken as an infant to Japan. I was raised with twelve others. When the Dr. Anderson died, Isamu chose me as the heir to the secret."

Director Fury didn't know how to respond to that. None of them did. It was a very blunt description, if any. Natasha nodded, though, her instinct taking over. "Alright, so I'm guessing this secret is very important if only two people at a time are allowed to know. Why? What makes it so important?"

Clint, who knew what Natasha was trying to do, started to say, "Nat, don't even—" but he never finished his sentence.

The girl didn't skip a beat. She didn't even hesitate before answering automatically, "Because the secret will change the world one day. It could mean the difference between global wipeout and survival of the human race."

"Why can only two people at a time know, Kid?"

"There's a group of terrorists out there. They're after the secret, and if a bunch of people know, it just makes their job of getting the secret easier. With only two, we can hide together, and therefore they're harder to find. The reason the two stick together is so the terrorists can't use bombs to try to kill us, which could potentially harm a bunch of innocents. If they want the secret, they have to attack us on foot. They normally kill the older of the two and try to take the younger one hostage. Wherever they take them, the person is tortured until they give the secret. But no one gives the secret. The only one they managed to capture died before telling, and that was Dr. Anderson."

Natasha took a second to digest that. "Alright. So, this secret. I get that it's a _really_ big deal. But something like that… shouldn't SHIELD have noticed already?"

The girl shook her head. "This was all happening in Japan. It was a project that SHIELD didn't really think needed supervision. That's why you never knew."

"What project was this?" Natasha threw out casually, confident she was about to get some results.

The girl hesitated. "Why?" she asked cautiously.

"We may not have supervised it, but we could still have record of it," Natasha answered, secretly impressed by the way the girl had avoided giving too much information. "If there's something that could threaten the world, we need to know. We defend the world from stuff like this, Kid. We want to help. You _can_ trust us, you know."

The girl didn't say anything for a moment. She just looked into Natasha's eyes, as if searching for something. Finally, she said, "You're well spoken. I don't trust you completely. Not yet, at least. You have to earn my trust. But I think I can tell you part of the secret, for now." Fury gave Natasha a sideways glance, as if to say, _Nice one, Romanoff._

"Not here, though," she said. "I don't feel safe in the open like this. They could be listening."

Director Fury nodded. "That's fine, Kid. Let's get you some medical attention first. We'll take you to the nearest SHIELD headquarters, get you fixed up, and then we can have a nice, old-fashioned, face-to-face chat. Sound good?" She nodded. "Good. Barton, get her to the medics. We takeoff in five. I want you, Coulson, Romanoff and Hill in the same quinjet as her. Any other agents with you need to be approved by Hill. Understood."

"Yes, sir," Barton replied, shifting the girl into a more secure position in his arms. "Medics, takeoff, Coulson, Tasha, Hill, anyone else goes through your assistant."

"Good. Get moving, I don't want any delays."

* * *

They were flying north, into the Sierra Nevada. It was where one of SHIELD's newest headquarters was, the one that everyone was calling the "tech savvy" center. Natasha hadn't been there before, but she couldn't say she was eager to get there for the new equipment. She just wanted to talk to the girl.

"So, what should we call you?" Clint mused sitting on the floor next to the girl. "I mean, obviously we can't just call you 'Kid,' that's too much of a boy's name. Hmm. What do you think, Coulson?"

"I don't know… Clara?" Phil replied, spreading his hands in a gesture of defeat. "It's not like I've named anyone before."

"Nah. Clara make her sound too girly. What about you, Hill? Any input from the assistant?"

Agent Hill shrugged. "She's from Japan, right? Give her something Japanese."

"America, originally," the girl corrected quietly.

"Then… how about Elizabeth?"

"Elizabeth?" Clint asked incredulously, raising his eyebrows as if he couldn't believe she'd just suggested the name. "Why Elizabeth? How's that American?"

"My cousin's name is Elizabeth," Agent Hill defended. "Hey, if you don't like our suggestions, you come up with a name."

"Might as well," Clint said, sitting up straighter. "Now, who do you remind me of the most?"

Natasha rolled her eyes and cast a glance out the window. She couldn't see much, just the dark outlines of the mountains against the night sky as they got closer to their destination. "Hmm… let me think. You can go from being completely silent to really talkative in seconds… Phil."

Coulson raised his eyebrows. "Really?"

"Yep."

The girl apparently agreed with Phil, though, because she shook her head. "Phil is just as much of a girl's name as 'Kid' is."

"Oh, picky, picky, picky. Let's see… Red hair, green eyes, very pale, raised in another country for one specific purpose. And incredibly clever. Remind you of anyone, Cap?"

Steve, the only other agent Hill had allowed to join them, smiled. "Yep. I can't put my finger on it though… I know I've seen her recently."

"Yeah, me too…" Clint said, a mischievous grin on his face. "Hill?"

"I know who you guys are talking about, but her name… gosh, I can't remember!" Hill said, obviously trying not to laugh. "How about you, Phil?"

"Nope, not a clue," he replied, starting to shake with silent laughter. "Ask the pilot."

"Hey, do you know who we're talking about, up there? Red hair, green eyes, possibly Russian?" Clint called up to the cockpit.

"I'm afraid I have no clue. Sorry guys," the pilot called back. "Let me call Director Fury, see if he knows."

By now, Coulson, Hill, Steve and Clint were all howling with laughter. The girl and Natasha were the only two who didn't seem to appreciate the joke. "Hey, Director, this is Whiplash Two, asking a very important question, do you copy?"

"What is it?" came Fury's deep voice through the comms.

"Well, the guys here are trying to name our survivor, and they're trying to name her after someone they know. Do you recognize the description of red hair, green eyes, and possibly Russian?" he asked, trying to keep his voice from breaking.

There was a pause as Fury thought his answer over. "Well," he said, "I'm not the expert with Russians. Ask Romanoff, maybe she could tell you."

There was another wave of laughter, and Natasha finally had enough. "Bela!" she shouted.

"What?" Clint asked, his amusement turning to confusion.

"Bela," she said again. "You said you wanted a Russian name, she's Bela now."

"But—"

"Nope. She's Bela."

"I like that," the girl said. "Bela. That's very good. Thank you, Agent Romanoff."

"What – I thought we were having a group discussion, here!" Coulson protested.

"Well, I think she looks less like a Natasha and more like a Bela." Agent Romanoff paused. "That is what you were planning on naming her, isn't it? Natasha?"

"I was thinking along the lines of 'Tasha Two,' to be honest," Clint admitted. "You have to admit, she's your perfect Mini-Me."

"Mini-Me or not, she's Bela, and that's final." Natasha gave Clint a look. "Understood?"

Clint snorted. "Jeez, Nat, someone's opinionated."

"I'm Russian, Clint. We're known for it."

* * *

As soon as they landed, Bela was taken to the infirmary, with Clint and Natasha to keep the other agents from getting nosy. Natasha kept a steady stream of innocent questions going between the two of them as the doctors slowly splinted her foot, every once and a while getting a questioning glance from Clint. "So, what do you do for fun?" Natasha asked.

Bela thought for a moment. "I draw. I weave bracelets. I read. Isamu didn't like anything that was too loud. He said it was good practice for when we were found."

"How old was he?"

"Well… Dr. Anderson was thirty two when he first told Isamu the secret, and Isamu was eight. They managed not to get caught until Dr. Anderson was fifty three, when he was caught and tortured, which is twenty one years. He died before they could get it out of him."

"How do you know that he didn't tell them?"

"Because the terrorists keep following us. That means they don't know the secret. Anyway, I was four then, so that means seven more years… Isamu was thirty six when they got him."

Natasha felt bad for the girl and her guardian, but she pushed aside her emotions and kept digging. "How did they find you?"

"They know what Isamu looks like, and they have people everywhere. They found us in Japan, so we went to Canada. We were there for about four years, just traveling around and laying low. They managed to track us down in St. Stephen, New Brunswick, and we barely got away. Isamu decided that Canada was too dangerous then, so we crossed the border into Maine. From there, we started to make our way west, and that's how we ended up in that office building."

"Why were you there?" Natasha asked.

Bela sighed. "Dr. Anderson had several colleagues who worked in that corporation. Isamu was trying to get help, because we had been attacked the day before that in some little town in Nevada. We weren't fast enough, though. They caught up."

Natasha nodded. "Well, you're safe now. SHIELD does stuff like this a lot."

Bela smiled sadly and shook her head. "I'm never safe, Agent Romanoff. They know what I look like now, and that SHIELD has me. They never give up like that. They didn't find me, so they decided to let you do all the hard work for them. They'll be coming for me soon."

Natasha paused. She had never heard an eleven year old talk like that except — "She sounds almost like you, Nat," Clint said. He meant it jokingly, but Natasha could hear in his voice that Bela's warning had struck a nerve.

"At least we'll be prepared, though," Natasha said, her voice sounding more confident that she felt. "We'll warn Director Fury. He'll know what to do."

"Warn me about what?" came the Director's voice from behind them.

"Speak of the devil," Clint said. "Bela here was just warning us that the terrorists will know where she is. They'll be coming soon."

"How do you know?" Fury asked the girl.

She shrugged. "They have their ways. They gave up looking too quickly. They'll have had someone watching to see if you found me. Then, they'd have tracked your aircrafts back to your base. Now it's just a waiting game to see when they strike."

Fury paused. "You're sure?"

"Positive. I've never been wrong before."

The Director sighed and shook his head. "I'm not sorry we pulled you from that wreckage, but this is causing more trouble than we bargained for. Now, your leg patched up?" Bela nodded lifting her leg slightly. "Good. Walk with me, you three."

Clint was pushing Bela along in a wheelchair, Natasha by his side, and Director Fury led the way. It turned out that their destination was a lunch/break area only about thirty seconds away from the infirmary doors. "You want something to drink?" Natasha asked.

"Coffee would be nice," Clint said.

"I'm fine, Romanoff," Fury replied, pulling up a chair to one of the tables.

"Just water, please," Bela said.

Natasha went to go get their drinks as the Director asked the million dollar question. "So. You say you have a secret. One that can change the world."

"Yes, sir," Bela said.

"And you were going to share part of that secret with us?"

"Yes, sir. Not all of it. Only what the terrorists and the rest of the group in Japan know."

"Well, we're all ears," Fury said. Clint nodded his thanks to Natasha as she handed him his coffee, and Bela gave her a smile before taking a quick sip. Then her grin changed to a frown. "What is it?"

"Nothing," Bela said. "I'm pretty sure it's nothing."

Natasha sat down next to Clint, who winced at the heat of his coffee. "You sure?"

"Yeah…" Bela didn't sound sure, but Director Fury didn't press it. "Dr. Anderson was one of twenty six scientists in Japan working to find a cure for cancer. I don't know specifically what type of cancer, but it was all happening at a laboratory in Japan. There were scientists from thirteen different countries all working together to find the cure. Those countries were the USA, Japan, Russia, the UK, France, Australia, China, Germany, India, Canada, Brazil, Italy, and South Africa."

Natasha took a sip of her water and frowned. Something tasted off. That must have been what Bela had tasted. Natasha dismissed it as the taste of the water in the area and continued to listen to Bela's story.

"Dr. Anderson was the only representative from the USA, and he was a genius. Within the first few months, he had a formula designed specifically to target the cancer cells and kill them without harming the patient. The first few tests were successful. The patients were in great health in about two weeks, and that was that. But the one of the scientists got sick. Her vital organs started to shut down. It only took about three days before she was in critical condition, and after that it was only a matter of days before she died. On closer inspection, the other scientists realized that a mutated form of the cure had gotten into her system and killed her. Dr. Anderson had found a cure for cancer, but he'd also engineered a virus.

"One by one, the other scientists caught it, and soon it was just Dr. Anderson, one of the Russians, and a few from Europe. The virus had been quarantined, but they still didn't have a way to stop it from killing them. Until Dr. Anderson tried a second cure – and it worked. This time, the formula didn't mutate. It saved all the remaining scientists and the test subjects. They killed off the virus, and things were back to normal. But Dr. Anderson had kept a sample of the virus, just to do a little experimenting, and it was stolen by those terrorists."

"Why would they want a virus that could kill them off?" Clint asked, trying his coffee again.

"This certain group of people believe that if someone is different than they are, that person should be killed. They took the virus to cleanse the Earth of everyone different. But they didn't managed to get the cure. That's why they chase me. Because every sample, everything written, everything that could help the terrorists make the cure was destroyed. It put the terrorists and the scientists in a stalemate. On one hand, the terrorists couldn't release the virus without killing their own people, and on the other, Dr. Anderson couldn't tell anyone the cure."

"So the real secret—" Fury said.

"That's the recipe for the cure." Bela took another sip of her water, and her eyes grew wide. Just as Natasha was about to take another sip, the girl knocked the paper cup from Natasha's hand, and it fell to the floor with a thump and a splash.

"Whoa, what's the matter?" Clint asked. Bela looked like she was going to have a panic attack.

"They've found me," Bela squeaked, trembling. "They made their move."

"What's going on? Why's my water all over the floor?" Natasha demanded, grabbing a fistful of napkins to mop up the mess.

"Agent Romanoff, I'm so, so sorry," Bela whispered, tears starting to slip down her cheeks. "I should've known from the first taste. But they went for the plumbing."

"What are you saying, Bela?" Clint said, confusion on his face. When she didn't answer, he looked at Natasha. "Nat? What's wrong?"

The color had drained from Agent Romanoff's already pale face, and she could feel dread settling in her stomach. "What Bela means," Natasha said, trying to keep her voice level, "is that the terrorists got into the plumbing systems and poisoned it." She looked her partner in the eyes and said, "Which means that I have the virus."


	3. Chapter 3

**Sorry for the wait! I got caught up with life and had to take a break from writing. Anyway, enjoy and feel free to review! I'd like some constructive criticism to make Virus better. :)**

* * *

**Chapter Three: Lockdown**

"Quarantine the base," Director Fury ordered sharply as he, Natasha, Phil, Clint and Bela made their way down the main hallway. Phil nodded and turned sharply to the right, into a dark room. A few moments later, a woman's voice echoed across the base, ordering everyone into the innermost building and shutting down all transportation in and out of the base.

"I'm sorry," Bela whispered.

"You _will_ be if you say you're sorry again," Natasha growled threateningly. Bela fell silent.

"Romanoff, I want you in the hospital ward right now," Fury said over his shoulder as they passed an interrogation room.

Natasha frowned. "I'm fine, Director, really—"

"Not if you've got a highly contagious disease and are exposing the rest of the agents in this base," Fury said simply. "And I don't care how much you hate hospitals, Romanoff."

With an irritated huff, Agent Romanoff peeled away from the group and made her way to the medical area. Fury sighed. "Barton, I need you to round everyone up in the main meeting rooms and brief them on the situation. Keep details to a minimum. Medics should be fine, the water used in the hospital comes from a separate supply and has been as well as possible."

"Yes sir." Clint started to turn away, still wheeling Bela, but Fury stopped him.

"I'm taking Bela to the laboratory in medical. We need her working 'til she drops."

"Until I – drop?" Bela asked, confused.

Fury gave her a sideways glance. "You drank the water, too, Bela. You've got the virus."

"Oh. Oh, no, sir, you don't understand," Bela said quietly, her eyes widening. "All the children who were candidates to learn the cure had to build up an immunity. They would get us sick every few weeks and give us small amounts of the cure during the day after it had taken full effect. Isamu went through the same process while he was with Dr. Anderson, and he kept building up my immunity, too. The whole point was to teach our immune systems to fight the virus."

Director Fury nodded. "Dr. Anderson thought this through very carefully, didn't he?"

"He had to. The people who know the cure are no use dead, sir."

Clint squeezed one of the girl's shoulders. "You know, I like you, kid. You're always so serious about this kind of thing."

Bela turned her intense green eyes on him. "But… I thought my name is Bela now."

Clint rolled his eyes and started to walk the other way, back towards his destination. "'Kid' is your nickname, then. See you around, kid." Bela smiled and waved. Then Fury began wheeling her away.

Isamu had never been a religious kind of person. He'd never known what to think. But he'd taught Bela of all the religions he knew of at one point or another, and she could remember them all. _Please,_ she thought gazing at the ceiling helplessly, _if there is someone out there, someone listening… please let Natasha and Clint and Phil be okay. I've already lost Isamu – don't think I could bear to lose anyone else._

* * *

"Alright, ladies and gentlemen," Agent Barton called from his position on the highest table in the main assembly hall, raising his hands for quiet. The buzz of the agents' worried mutters died down immediately. "I bring news on our current situation."

"What is this, Barton?" Agent Hill called. "Fury never issues orders for everyone to gather up, he calls on the highest ranking agents."

"Well, I'm sorry to say that this is not a regular meeting, Agent Hill." Clint took a deep breath before continuing. "Earlier this morning, as you may recall, a team of SHIELD agents went to the site of a recent terrorists attack to search for any survivors or clues as to who the attackers were."

A low hum of whispers started up again, but Clint raised his voice over it and the others fell silent once again. "As you may know, we found only one survivor. We brought this survivor to this base and are now questioning her as to who the attackers are. Unfortunately, we were not as quiet about our actions as we should have. We were followed by these terrorists to this base and are now under extreme threat from said terrorists."

"Is this an evac order?" One of the agents called up from the crowd. "If it is, why did we shut down all transport systems?"

Clint shook his head. "This is not an evac order, this is more of a 'stay put and try not to breathe on each other' order. Earlier this evening, Director Fury was alerted by one of our people that our water supplies have been contaminated. Anyone who has come into contact with this water in the past few hours has been infected with the contaminant. It is a virus, and one that spreads incredibly fast at that. We're quarantining this base until further notice. No one is to come or leave, no one is to come into physical contact with each other, and above all, DON'T DRINK THE WATER! That means you, Brown!"

Agent Brown, a level two agent, turned scarlet and dumped a cup of tap water she'd just poured for herself back into the sink.

"Thank you." Agent Barton cleared his throat. "If you begin to feel nauseous, lethargic, your vision is impaired or your muscles start to ache, please make your way to Medical. And no contact with the outside world!" he warned. "Director Fury has reason to believe our communication systems are bugged." So, for the next fifteen to twenty minutes, the SHIELD agents sat and chatted quietly. Then…

"Oh, my stomach…" moaned one of the scientists, and before anyone could react, two of the others were coated with what had been his lunch.

"OUT, all three of you, out! No one touch it, treat it like its radioactive!" Clint shouted. "No one is to go near it!"

The three scientists out, the sickest supported between the other two, and the agents made a wide path for them to get through. It wasn't long after when a secretary staggered out limping, followed by a guard stumbling blindly forwards. One by one, the crowd slowly trickled out, thinning finally to just over half of the base. Maybe ninety agents, scientists and assorted workers remained.

Clint sighed and shifted his weight, sitting comfortably on the table. "How much longer can we last?" he asked in a whisper to no one in particular. Phil, sitting in a chair at the table, shook his head. Finally, a familiar voice rang through the buzz.

"Agent Barton," Director Fury called, making his way through the crowd and carefully stepping over the scientist's mess on the floor.

Clint sat up straighter. "Yes, sir?"

"I'd like you down in Medical. Coulson, you take over here." Coulson nodded.

"What's wrong in medical?" Clint asked.

Director Fury shot him a sideways '_don't-ask-questions_' glance, but he replied, "Agent Romanoff is having… an unusual reaction to the virus."

_Tasha!_ Her name echoed through his head, filled with worry. Clint immediately felt more alert, and he slipped from the table to follow the director to the medical center. A voice in the back of his head spoke to him in a panic, voicing his worst fear. _She might not make it. What will I do if she doesn't make it? Bela – Bela said it kills in days. What if it gets her before the cure does? What if—_

_Shut up_, a stronger voice in his head growled_. I won't let that happen. Don't worry, Nat. I'm on my way._

* * *

Bela sat quietly, staring at the fancy lab equipment laid out in front of her. She'd never had to use such fancy stuff before… _How do I even work this stuff?_ Bela asked herself. Then she shook her head. _Doesn't matter. I know the recipe. I'll be fine. It'll be okay._

She wheeled herself over to a tray of syringes. "Are these clean?" she asked the medic who Director Fury had allowed to stay in the small room with her. The woman nodded, watching her curiously. Bela nodded, satisfied, and set a few in her lap. With a sigh, she pushed herself over to a clear counter space and set them down.

"I can bring you things, if you want," the blonde-haired doctor offered. "It'll be easier on your arms."

Bela nodded. "I need a petri dish and about a gallon of the infected water, please." She tried to ignore how odd the sound of her Japanese lilt probably was to the woman, but she couldn't help but feeling out-of-place. As the doctor hurried to fulfill her request, she thought of the nursery back in Japan. How the nurses had spent countless hours teaching them the languages of each represented country. She'd learned them all easily, but to have a passable accent – _that_ was hard. She'd had to learn quickly in Canada, and then in Maine. But she couldn't bear to part with that soft Japanese touch. It was a part of her and she didn't want to let it go, even if it set her apart.

"Here we are," the scientist said, setting a big pitcher of the water and a petri dish down on the counter next to the syringes. "Anything else?"

"No, ma'am. Thank you." Bela wheeled herself over to a cabinet and started examining the contents carefully.

"Whoa, I thought that was all you needed!" protested the woman, brushing a strand of blonde hair from her eyes and walking over to see what Bela was doing. "I can get things for you faster—"

"It isn't necessary," Bela said simply. "I'm not allowed to share the cure's recipe with anyone, ma'am."

"But we could make more of it faster!" the scientist said, exasperated. "Come on, it can't be that big of a secret!"

Bela turned her intense green eyes on the woman and trapped the blonde in her gaze. "No disrespect, ma'am, but I'd like you to leave. You're slowing me down."

"I wouldn't be if I could help," the woman said quickly.

"Perhaps I should call Director Fury," Bela mused, "and have him deal with you, miss."

The scientist gave her a look of disbelief. Finally, she turned, muttering curses lightly under her breath, and stalked out of the lab. With a sigh, Bela turned back to the cabinets. She ran through a list of chemicals and hormones in her head. Slowly, she brought each of them back to her counter until she had an odd assortment of ingredients spread out before her. Bela thought for a moment. _A microscope would help_, came a helpful thought.

Tiredly, she reached for the nearest one, pulled it closer, and plugged it in. She pulled a piece of twine from one of the pockets in her borrowed SHIELD uniform. She'd been planning to use it to make a bracelet, but it would be more useful to tie up her hair. Pulling the auburn-red curls up and off of her neck, she twirled it into a clean side braid and tied it neatly with the blue string. Turning back to the soon-to-be cure, she took a sample of the water in a pipette and let it trickle into the petri dish.

She risked a glance at the clock and sighed. 11:35 P.M. At least half of the staff would be infected by now, if not more. She had a lot of work to do.

* * *

Clint and Director Fury made their way into the infirmary. The Director stopped at the keypad to the quarantine area and pressed his hand to the scanner. With a quiet swoosh, the doors slid open and Clint walked inside, his pace quickening when he saw a scramble of nurses and heard a loud, continuous flat line. "Romanoff?" he asked the secretary.

The woman had a guilty look in her eyes, and if she hadn't been wearing a mask over her mouth and nose, Clint would've seen her grimace.. "Um…"

"What?" Clint demanded. "Where is she? What's wrong?"

"Well…" the secretary said nervously, readjusting her mask. "We've had a slight issue…"

"JUST TELL ME!" Clint snarled.

"We… well… it's that room, there. You have to see it for yourself." The secretary averted her eyes.

Clint brushed past a panicked nurse and into the room. And there, much to his disbelief, he saw it. He knew why the secretary hadn't been able to say, and why the nurses were panicking, and why there was a seemingly endless flat line ringing through the infirmary. He made his way over to the hospital bed and stared down at it.

Natasha Romanoff, the Black Widow herself, was gone. But 'gone' doesn't necessarily mean 'dead'. In Natasha's case, 'gone' meant that she'd escaped her hospital room by climbing out the air vents and leaving no evidence behind but a rumpled hospital gown and a large metal grate from said air vents in her place.

For a few moments, he stared at the scene in a stunned silence. Then, he whispered, "Tasha, what've you done?"

* * *

Phil sat on the table, tiredly rubbing his eyes and yawning. The last agent to run for the infirmary had been, what, thirty-six minutes ago? No, thirty-seven. His job had turned into a waiting game, one where your agents were so bored that some of them were taking bets on who was going to yell, "I can't see!" or lose their lunch next.

"I think it'll be you, Barnes," a pretty Asian scientist said, tossing her long black braid over her shoulder. "I saw you earlier, all cuddled up with Agent Langley over there. How long was it since she left? Forty-five minutes? Well, you'll be heading her way pretty soon."

"Please, Hendrix," a guard with red/blonde hair replied with a snort. "If anyone's leaving, it's you. I mean, come on! You were taking a drink break twenty minutes before the alarm sounded. You're gonna have a late reaction, I know it."

Agent Coulson sighed and pinched the bridge of his nose. "Twenty minutes," he muttered, closing his eyes. "That's all they needed to get bored. And now they're taking bets on who's most likely to come down with a deadly disease next. Good lord, what has SHIELD come to?" He knew that SHIELD agents these days weren't exactly all model citizens, but did Fury have to recruit such idiots?

His thoughts were interrupted with a beep from his comm unit. "Coulson," he said.

"Coulson, this is Barton. We've got a situation in Medical, and we need you down here," came Clint's instant reply. "Put Hill in charge."

"And bring the Cap, Agent," Director Fury said. "Tell him he's back on duty."

And without further instruction, the connection ended. "Rogers, with me," Phil said as he stood up, all traces of weariness replaced with purpose. "Hill, you're in charge." He tossed Maria his comms unit and left the room at a quick pace, weaving his way carefully through the crowd of agents.

"What's happening down their?" Steve asked, falling into stride next to Phil.

Agent Coulson sighed. "They didn't say, but I have a sinking suspicion that it has something to do with Agent Romanoff's condition."

* * *

Bela sat back and gave a yawn. The cure seemed to be complete. Then again, she could never be sure. She'd only made the cure twice before, both times in smaller quantities.

The blonde scientist poked her head in for what seemed like the millionth time that night, and Bela glanced up at her. "Can I help you, miss?" she asked dryly. "Or have you come to tell me that I need to work faster?"

The woman gave her a withering look. "I'm just here to update you on the situation, ma'am. Almost one hundred and twenty agents are now ill with your virus, and you still haven't come up with the cure for us yet. How soon until the first batch is ready?"

"Soon. Perhaps in fifteen minutes. Come back then," Bela said calmly. She turned back to her microscope and focused the lens more closely on the cure's components. The scientist just rolled her eyes and closed the door behind her with a soft slam.

Bela wheeled herself over to the door and locked it before going to the nearest sink and poured a fresh gallon of the infected water into a vial. She took it back over to the petri dish and tipped some of it into her newly made remedy. She put one of her emerald-green eyes up to the eyepiece of the microscope and allowed herself a small smile.

It was working.

Bela took the petri dish and swirled it around a bit, before leaning over and dumping it into the gallon of water. In about three minutes, all the virus cells in the pitcher would be replaced with the cure. That was the way Dr. Anderson had engineered the cure. Bela absently glanced at the clock. 12:01. Well, a fresh day and a fresh start. By ten at the latest, the staff would be virus-free.

_Thump_.

Bela's head jerked up. Had the terrorists come for her?

_Thud_.

She looked around quickly for the vent, and yes, she could see something – or someone – moving around behind the grate. She sat up straighter, and in an eastern language she'd been told was spoken by the terrorists, she said, "_If you want the cure, you'll have to come take it from me_."

There was a pause. And then there was a crash.

A streak of black cloth and red hair tumbled to the ground, cursing in Russian, before straightening up with a wince. "Natasha?"

"Bela…" Agent Romanoff staggered over to the counter and made her way over clumsily. "Bela, I can't do it anymore. The virus… it's making me hallucinate."

"Calm down," Bela said, taking Natasha's hand in her own. "Just focus on what's real. I'm real. Pay attention to my voice, all right? You'll be fine." Natasha's skin, although usually pale, was even paler, and the SHIELD agent was covered in a cold sweat.

"They – they were going to give me some medication, to make it stop, but…" Agent Romanoff shivered. "I couldn't stand the sight of that needle. I'm losing my head," she whispered, sinking to the floor.

"I can make it stop. I have the cure here, it should be almost ready."

Natasha gasped and started whispering deliriously in Russian. From what Bela could understand, she was repeating to herself over and over again, "No needles, no needles, no needles no needles."

"No needles," Bela promised. "You just have to drink some of this." She filled a paper cup with the solution and handed it to Natasha, who gripped it tightly.

"No needles?"

"No needles."

Natasha raised the cup to her lips and drank it slowly. She set the empty cup on the counter and pulled her knees to her chest, wrapping her arms around herself until she was in the fetal position. Bela smoothed her ruffled red hair and murmured to her soothingly in Russian, the way the nurses had with the Russian boy back in Japan. Soon, Natasha was sleeping, her head cradled gently in Bela's lap. "Just sleep. The cure works best when you're resting," Bela said.

Then the door was beaten down with a crash.


End file.
